Eno River Outfall and Lift Station
Eno River Outfall and Lift Station
Eno River Outfall and Lift Station
Eno River Outfall and Lift Station

Eno River Outfall and Lift Station Upgrades

The Eno River Watershed was reaching capacity and Durham County upgraded to accommodate growth in the basin. The solution included 25,000 linear feet of 24-inch to 48-inch gravity sewer outfall replacement along the Eno River in the City of Durham to the Eno River Lift Station. The Eno River Outfall and Lift Station Upgrades project involved the upsizing of over 17,000 linear feet of sanitary sewer outfall pipe along the Warren Creek and Eno River, along with upgrades to the Eno River Lift Station bringing the station’s firm capacity up from 15.8 million gallons per day (MGD) to 24.4 MGD.  Upgrades at the pump station included adding a third 500-horsepower pump, removal of existing bar screens and replacement with mechanical channel grinders, hydraulic improvements to the incoming outfalls, installation of a permanent jib crane for grinder removal, replacement of the existing downstream flow meter, installation of a permanent pump station bypass system, and electrical and SCADA improvements.

Due to a lack of accurate records depicting the mechanical design of this pump station, along with a non-functional flow meter, extensive preliminary monitoring and design was required to provide an acceptable level of upgrades at this facility.  In addition to performing field tests to gather data on pump station operations and determine pump curves, our design team facilitated several collaborative workshops with City personnel representing both the Engineering and Operation & Maintenance Departments managing this facility.  These meetings provided further insight as to the needs for this station.  Results from the field testing, along with outcomes from these workshops, were documented in a Lift Station Alternatives Design Technical Memorandum, which set the basis for the interim upgrade at this station.

In addition, a Flow Projections Technical Memorandum was authored by our design team to document the flow projections for “interim” upgrades, future upgrades, and long range planning upgrades based on results from the City’s sanitary sewer model.  During construction, our design team performed a structural assessment of the interior of the wet well and influent chambers to determine the structural integrity of these structures, as well as performed internal measurements to document geometry in order to further optimize the limited hydraulics across the station’s superstructure.  Findings were documented in several technical memorandums, including a structural assessment memo recommending future structural rehabilitation needs, a summary of a computational fluid dynamic model performed on the wet well and influent chambers in order to determine how best to optimize on the pumping hydraulics across these chambers, and a pump station future recommendations memo documenting future needs for this station as flows continue to increase across this basin.

This project was completed ahead of schedule and under budget.

Project Details

Client City of Durham
Location Durham, NC
Categories State/Local, Wastewater , Water
  • 2023 Engineering Excellence Honor Award, ACEC/NC